1. Field of the Invention
The present invention is relates to a process for production of an alcoholic beverage which is obtained by alcoholic fermentation with yeast, and in particular, with improving the flavor of an alcoholic beverage by employing phospholipase in a process for production of alcoholic beverage.
2. Related Art
There is a process for the production of an alcoholic beverage employing a starchy material there have which is saccharified and then subject solid-liquid separation to prepare a fermentable liquid. The fermentable liquid is fermented with yeast as in the case of manufacturing whisky or beer. In of starchy material process, a and is saccharified subject to fermentation with other yeast carried out with mold rice "koji" or enzyme and yeast, as in the case of manufacturing Japanese "sake" or Japanese distilled spirit "shochu".
In other processes for production of alcoholic beverages, starting material contain sugar. In these process, starting materials prepared are for fermentable liquid and the liquid is fermented with yeast as in the case of manufacturing wine or cider. In any of these processes, the flavor of alcoholic beverages results mostly from the ester formation by yeast during the fermentation. However, rice and other starting materials for alcoholic beverases, especially barley, wheat, rye, corn, etc. contain a relatively large amount of lipids, and it is known that unsaturated fatty acids in these lipids inhibit ester formation by yeast.
Accordingly, various methods for the removal of unsaturated fatty acids have been proposed as the means of improving the flavor of alcoholic beverages. There is employed, e.g., a method for filtering mash. According to this method, though the amount of unsaturated fatty acids can be reduced to some degrees, it is impossible to reduce the amount of unsaturated fatty acids to such a degree as the increase of flavor component may be expected. In the manufacture of Japanese "sake" or Japanese distilled spirit "shochu", the amount of unsaturated fatty acids can be reduced by steaming the raw material. According to this method, although the unsaturated fatty acids in the outer layers of cereal grains are removed, those in the inner parts of the grains cannot be removed and the complex lipids consisting mainly of fatty acids are reduced in quantity only by 10 and several percentages. In the manufacture of Japanese "sake" or Japanese distilled spirit "shochu", a method wherein the polishing rate of raw material is increased has also been used, but it is not necessarily an economic method and even if polishing rate of raw material is increased, the unsaturated fatty acids in the inner parts of cereal grains cannot be removed, and the method is not very efficient when a raw material containing a relatively large amount of lipids is used.
In Japanese Unexamined Patent Publication No. 58-35674, a process is described for the manufacture Japanese "sake" rich in flavor, in which the starting material, rice, is steeped in water and lipase is added to free fatty acids. The steeped rice is steamed to remove the free fatty acids, especially unsaturated fatty acids.
In Japanese Unexamined Patent Publication No. 62-111695 (European Patent Publication No. 0219269), a process for the manufacture of starch syrups employing phospholipase. The purpose of this process is the improvement of filterability, lowering of foam-formation, clarity of filtrate, etc. There is no suggestion at all as to whether or not that technique may be utilized for the manufacture of alcoholic beverages.
In Japanese Examined Patent Publication No. 59-21594, is described a process for the manufacture of Japanese distilled spirit "shochu" by employing a plurality of enzyme preparations including amylase, protease, and cellulose. The purpose of this process is the simplification of process and the improvement of "shochu".
In Japanese Unexamined Patent Publication No. 62-55069, a process is described for the manufacture of alcoholic beverages obtained by alcoholic fermentation by yeast in which corn grits are treated with amylase, protease and lipase.
However, no process for the manufacture of alcoholic beverages by the employing of phospholipase has been known.